Re: Re: [PATCH] backports: crypto user - make NETLINK_CRYPTO work

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Apr 08, 2021 at 07:11:48PM +0000, Jianmin Wang wrote:
> On Mon, Apr 05, 2021 at 16:14 UTC, Greg KH wrote:
> > On Mon, Apr 05, 2021 at 01:55:15PM +0000, Jianmin Wang wrote:
> > > There is same problem found in linux 4.19.y as upstream commit. The 
> > > changes of crypto_user_* and cryptouser.h files from upstream patch are merged into 
> > > crypto/crypto_user.c for backporting.
> > > 
> > > Upstream commit:
> > >     commit 91b05a7e7d8033a90a64f5fc0e3808db423e420a
> > >     Author: Ondrej Mosnacek <omosnace@redhat.com>
> > >     Date:   Tue,  9 Jul 2019 13:11:24 +0200
> > > 
> > >     Currently, NETLINK_CRYPTO works only in the init network namespace. It
> > >     doesn't make much sense to cut it out of the other network namespaces,
> > >     so do the minor plumbing work necessary to make it work in any network
> > >     namespace. Code inspired by net/core/sock_diag.c.
> > > 
> > >     Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > >     Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
> > > 
> > > Signed-off-by: Jianmin Wang <jianmin@iscas.ac.cn>
> > > ---
> > >  crypto/crypto_user.c        | 37 +++++++++++++++++++++++++------------
> > >  include/net/net_namespace.h |  3 +++
> > >  2 files changed, 28 insertions(+), 12 deletions(-)
> > 
> > How does this change fit with the stable kernel rules?  It looks to be a
> > new feature, if you need this, why not just use a newer kernel version?
> > What is preventing you from doing that?
> > 
> 
> This problem was found when we deployed new services on our container cluster, 
> while the new services need to invoke libkcapi in the container environment.
> 
> We have verified that the problem doesn't exist on newer kernel version. 
> However, due to many services and the cluster running on many server machines 
> whose host os are long-term linux distribution with linux 4.19 kernel, it will 
> cost too much to migrate them to newer os with newer kernel version. This is 
> why we need to fix the problem on linux 4.19.

But this is not a regression, but rather a "resolve an issue that has
never worked for new hardware", right?

And for that, moving to a new kernel seems like a wise thing to do to
me because we do not like backporting new features.  Distro kernel are
of course, free to do that if they wish.

thanks,

greg k-h